THEORETICAL EFFECT OF REFRACTIVE ERROR AND ACCOMMODATION ON LONGITUDINAL CHROMATIC ABERRATION OF THE HUMAN EYE

Simple formulas based on reduced eyes have been developed to predict t he variation in longitudinal chromatic aberration with variation in am etropia or accommodation. Two formulas were developed, one for axial a metropia and one for refractive ametropia. The latter also served as a model for accommodation. The results using the formulas are in close agreement with results obtained using raytracing through more sophisti cated models. Combining the results of different methods gives the fol lowing predictions of change in chromatic difference of focus, between wavelengths of 400 and 700 nm, with change in each diopter of refract ive error or accommodation: axial ametropia 0.012 to 0.017 D (0.6 to 0 .9%), refractive ametropia 0.05 D (2.2 to 2.4%), and accommodation 0.0 4 to 0.05 D (2.1 to 2.6%). The chromatic aberration effects of correct ing lenses with low dispersion are intermediate in effect and opposite in sign to the effects of corresponding degrees of axial ametropia an d refractive ametropia.